Abstract

Much effort in behavioural genetics has been motivated by the hope that one day aspects of human behaviour will be explicable
in genetic terms. This hope is based on the assumption that the contribution of genetic and environmental factors to behaviour
can somehow be partitioned. However, recent advances in genomics, epigenetics, cellular and developmental biology and developmental
psychology have made it clear that such partitioning is biologically implausible. The functional significance of genes or
any other influence on phenotypic development can be understood only in relation to the organism–environment system of which
they are a part. Genes and environments are neither alternative nor independent causes for behavioural development.

Key Concepts

Genes, in and of themselves, cannot produce any behavioural outcome.

The function of a gene cannot be separated from the multiple contexts and environments in which it functions.

Contrary to the assumptions of behavioural genetics, genes and environment do not make independent contributions to behavioural
development.

Behaviour without genes is as impossible as is behaviour without an environment.

It is not possible to meaningfully estimate the risk of getting a given disease only on the basis of genetic factors.